Where can I get an application to work with my kml files?

You can view them online with GPS Visualizer. You load them directly with Viking GPS Analyser.

You can also convert them to GPX files using Viking or GPSBabel. Both are available from the Ubuntu repos. See Viking GPS Documentation for details.

If you're having problems with Google Earth in Ubuntu then you could try using Google Maps to view your .kml files.

As detailed on one of the Official Google blogs:

To view a KML or KMZ file on Maps, just go to Google Maps, and instead of searching for a geographical address like 1600 Amphitheatre Parkway, 94043, search for a complete Web address (including the "http://" part) of your KMZ file, like http://kml.lover.googlepages.com/cropcircles.kmz. Need your own web space to upload some files? Try Google Page Creator.

Google Page Creator has been shut down and Google now encourages to use Google Sites instead.

GPSPrune claims to support KML for read, view, edit and saving. It is java application and available for linux:

• https://apps.ubuntu.com/cat/applications/gpsprune/ - ubuntu's page for GPSPrune
• http://wiki.openstreetmap.org/wiki/GpsPrune - OSM wiki's page for GPSPrune with detailed description:

GpsPrune is a free, open source, cross-platform program to view and edit coordinate data like GPS tracks.

Viewing data with a map view using OSM maps

Editing data (delete individual points or sections, variable compression, combine and rearrange data, create and edit individual points)

GpsPrune can read files in the following formats: kml, including zipped and gzipped kml files and kmz files

GpsPrune can also save data to files in the following formats: kml and kmz files (kmz files can include photo thumbnails)